Study On The Construction Of Polyaniline/Graphene Oxide/Cuprous Oxide And Its Photoelectric And Photocatalytic Properties

Cuprous oxide（Cu₂O）is an intrinsic P-type direct band gap semiconductor with a band gap of about 2.2 e V,and whose theoretical photoelectric conversion efficiency can reach 18%.Currently,there are more mature applications in the fields of rectifiers and electroplating.In recent years,Cu₂O has been studied for the feasibility of photocatalytic degradation of pollutants and water splitting due to its advantages such as suitable band gap,convenient preparation,and non-toxicity.However,the reported catalytic efficiency of Cu₂O is barely satisfactory,and the semiconductor itself also suffers from some problems such as poor stability,which is susceptible to corrosion by oxidizing groups generated by photoelectrons.So,with the enhancement of the photocatalytic performance of Cu₂O as the core,the ternary composite composed of polyaniline（PANI）,graphene oxide（GO）and Cu₂O was designed for photocatalytic degradation.The experimental results turn out that the catalytic ability of the ternary composite is significantly improved compared to the binaries.The work was carried out in the following aspects:First,the unary Cu₂O and PANI were attempted to prepared.Pure Cu₂O particles was acquired by chemical precipitation,the effect of Na OH and temperature on the particles was preliminarily verified by changing the initial conditions,thus the morphology of Cu₂O could be regulated within a certain range.Subsequently,PANI was successfully synthesized by oxidative polymerization with assistance of ultrasound,the experiment turns out that the ultrasonic environment is the indispensable assistance in the formation of fibrous PANI.In addition,the concentration ratio of aniline to acid was examined to be an important factor in the adjustment of the PANI morphology.The well-grown PANI with fibrous morphology was obtained after the comprehensive grasp of these two factors.Subsequently,chemical precipitation was carried out for the growth of Cu₂O particles on the surface of GO.The successful preparation of this binary composite was confirmed by some characterization,moreover,the photocatalytic degradation ability and photocurrent were also investigated.Experiment results show that after being compounded with GO,the binary composite exhibits a photocatalytic efficiency about1.6 times and a photocurrent 3 times higher than that of pristine Cu₂O.After analysis,a conclusion was drawn that the dispersion of photoelectron and the adsorption of pollutant which dominated by GO are response for the enhanced catalytic performance,while the function of each component in the degradation process is preliminarily clear.Finally,the ternary composite was constructed through the preparation route of initially growing PANI on the GO surface,and then the formation of Cu₂O particles is taken place on the outermost layer.The characterization shows that the ternary composite was successfully constructed under the established route,in which PANI was fibrously distributed on the GO sheet,and the outermost surface were covered with Cu₂O particles.Experiments turn out that the carrier recombination rate of ternary composite is significantly lower than that of all the binary composites,which is due to the dispersion of GO on photoelectrons and the heterostructure established between PANI and Cu₂O.Besides,its catalytic efficiency can also be enhanced about 2.6 times higher on a basis of binary composites.After optimizing some component ratio in the ternary composite and comparing some results of binary composites,it was deduced that the enhanced photocatalytic performance is the result of the synergistic effect of adsorption and degradation,and a specific catalytic mechanism was proposed in detail.